Yes, potassium can be brittle depending on its form.
Boron is considered brittle in its pure elemental form.
No. Diamond is the hardest mineral and it is not malleable or plastic.
Zinc is malleable if you heat it to between 100 degrees C and 150 degrees C; outside that temperature range it's brittle. As to whether it's ductile...no, and that's immaterial anyway because the wire would break if you made any.
no, it is very brittle
Several metals are ductile and malleable.
malleable
Sulfur is brittle.
Doubtful. Ductile by definition means "not brittle, easily stretched, malleable".
Brittle
Brittle
Boron is considered brittle in its pure elemental form.
Most metals are not brittle.
No, it is a semi conductor so it is not ductile.
Non metals are brittle. They are neither malleable nor ductile.
Yes, metalloids are ductile they are also malleable, but is not shiny.
Barium is not malleable or ductile as it is a brittle metal. It does exhibit some lustre, giving it a shiny appearance.
Yes, zinc is brittle at room temperature but at higher temperature is is very malleable.